Linus Torvalds has reaffirmed that at this point he doesn't intend to pull KVMTool into the mainline Linux kernel.
KVMTool is the lightweight QEMU-free native KVM tool
. KVMTool has been developed by several open-source developers for nearly two years.
This tool for toying with KVM virtualization supports many features like SMP, various virtio features, QCOW2 read-write support, etc. The developers behind the tool have wanted to merge it into the mainline Linux kernel as a separate tool/utility (similar to Intel's turbostat and various other small user-space utilities living within the kernel tree) since this tool can stress the Kernel-based Virtual Machine components without QEMU.
KVMTool has been living within the "linux-next" tree, but hasn't been accepted by Linus Torvalds into his mainline tree, including for the latest Linux 3.7 merge window.
Torvalds has now explained his reasoning
for not accepting this pull: "I have yet to see a compelling argument for merging it. It's tons of code, it doesnt match the original "small simple" model, and I think it would be better off as a separate project."
So now if KVMTool is to survive it will likely just need to be maintained as its own separate project.